20W 12V Amplifier

Product Overview

The Pertronic 20W Amplifier (EVAC20W12V) is an evacuation amplifier with integral evacuation tone and message generator, together with a fault detection system. It is designed for use in emergency warning systems with supervised 100 Volt Line distribution systems. The amplifier delivers up to 20 Watts of audio power to the 100 Volt line.

The EVAC20W12V generates an evacuation tone with a voice message as specified in NZS 4512:2010. The amplifier is controlled by the BELL output of a fire alarm panel such as the Pertronic F1 or F4.

When in standby, the 100 Volt line is connected to the BELL circuit. This allows the fire alarm panel to detect short or open circuit faults on the 100 Volt line. The BELL circuit drives a small dc current through the 100 Volt line, which must be terminated with a suitable end of line resistor. It is important to note that every speaker connected to the supervised 100 Volt Line must be specially designed for emergency warning systems, with each speaker incorporating a DC blocking capacitor.


  • Generates the ‘Evacuation’ tone with verbal messages as specified by NZS 4512:2010
  • Can be directly mounted into the Pertronic F1 or F4 Conventional Fire Alarm panels, but can be used with any 12V Fire Alarm system
  • Activated when the BELL circuit voltage polarity reverses to the ‘Alarm’ state
  • In the ‘Normal’ state, the amplifier draws practically no current (less than 0.2 μA) and appears transparent to the Fire Alarm panel
  • The 100 Vrms line is internally connected to, and monitored by the panel’s BELL circuit 
  • The amplifier’s 100 Vrms line is short-circuit protected and is capable of driving up to 20W (13.7 Vdc supply) into connected PA loud speakers, eg. Pertronic PSS1 and PSSB401

Ordering Information

Product Code



Evac Amplifier 20W 12V